Centering-tool.



C. J. BORGESON.

CENTERING TOOL.

APPLICATION FILED AUG.6.1914.

1,152,070. Patented Aug. 31, 1915.

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C. J. BORGESON.

CENTERING TOOL.

APPLICATION FILED Aues. 1914.

1 1 52,070. Patented Aug. 31, 1915.

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UNITED STATES PATENT onnion.

CHARLES J. BORGESON, or SYRACUSE, NEW' YORK.

CENTERING-TOOL.

Specification of Letters Patent.

Application filed August 6, 1914. Serial N 0. 855,490.

To all whom it may concern Be it known that I, CHARLES J BoRsEsoN, acitizen of the United States, resldlng at Syracuse, in the county ofOnondaga and State of New York, have invented certain new and usefulImprovements in Centering- Tools, of which the following is aspecification. A

The purpose of this tool is to rapidly and I the additional stock. Ifthe center is placed with the applicants tool, a. minimum amount ofstock is necessary. The advantage of this device is the perfectcentering of a shaft or round piece of metal, and saving of material andlabor.

One embodiment of the present invention is illustrated in theaccompanying drawings, in which z Figure 1 shows an elevation of thecenter- 'ing tool; Fig. 2, a longitudinal section along line 22 of Fig.4; Fig. 3, a similar section along line 33 of Fig. 4; Fig. 4:, atransverse section along line H of Fig. 2; Fig. 5, a top plan view ofthe centering cup; Fig. 6, a top plan view ofa washer; Fig. 7, a topplan view of the cup securing ring; Fig. 8 is a view similar to Fig. 1showing the drill pushed forward; Fig. 9 is an elevation of a drillpress with the centering tool in position; Fig. 10, a section along line1010 of Fig. 9; Fig. 11 shows a drill positioning gage;.Fig. 12, alongitudinal section of the drill lock. Fig. 13 shows in axial section amodified form of the tool and Fig. 14, an end view of Fig. 13 with thebody portion removed.

The tool holder is provided with the usual tapered shank 19, which issecurely fastened in the body 18 of the tool holder. An outer,cylindrical casing 20 of about twice the length of the body surroundsthe latter with suflicient play to permit the one to slide on the other.Two L-shaped slots 24, situated diametrically opposite each other, arecut through the wall of the casing 20, and serve as guides forcorresponding studs 30, tapped into the body 18. lVith the parts in theposition shown in Figs. 1, 2 and 3, the studs abut against the upper endof the slots 2 L under the action of springs 36, as described later,thereby locking the parts together after assembling. At the inner end ofthe short leg of the slots isformed a recess 27 into which the studs 30drop on the pushing 111p and turning of the casing 20 on the body At thelower end of the casing 20 is revolubly attached the centering cup 22with a conical bore 41 contracting upward and terminating with acylindrical opening 36, which I preferably" provide with rifle grooves37, this for the purpose of preventing chips from the drilling to bind.The centering cup 22 is suspended on a ledge 38 provided at the lowerend of the casing 20. 7

An adjusting nut 25 of slightly smaller diameter than that of the casingis threaded on the upper end of the centering cup 22, and between thisnut and the ledge 38 is placed a washer 26. A small pin23, driven I intothe cup 22, projects upward, in order to engage with'one of a pluralityof holes provided in the washer 26, so as to key the washer and cuptogether. The nut 25 has a'threaded hole for a locking screw 40, which,when screwed in,projects downward slightly less than the thickness ofthewasher 26, and is positioned so as to engage with any one of the holes39 in the washer 26.

Patented Aug. 31, 1915.

Another washer 21 is placed between the end A of the casing and theflange of the centering cup 22, thus transmitting the axial pressurefrom the blank or bar 42 to be centered to the casing 20, when the blank42 has been placed between the centering cup 22 and the table cup 31.Bothwashers are made from some fairly soft material suchas fiber, brass,babbitt or the like.

' The utility of'this arrangement with the double washers will beevident. Ordinarily the nut 25 is not drawn up tight, but only enough topermit the cup 22 to revolve freely on the casing 20. When a blank ofhard material is placed between the two cups 22 and 31, the cup willfirst revolve with the tool casing while light pressure is put on andthe casing 20, while greater pressure is put on and the rest of the toolholder revolves. In case where no slip is provided between the casingand the cup, the conical surface of the latter, although hardened, mightbe abraded by the sharp edge of the blank 42. This is now avoided.

On the other hand, if a piece of soft material is going to be centered,the cup 22 might be permitted to revolve with the rest of the tool,asthe edge of the still-standing blank would not be able to injure theconical surface of the centering cup 22. In such a case, the nut 25would be drawn up tight on the centering cup 22 and locked thereto bythe screw 40 engaging a suitable hole in the washer 26, which, initself, as already described is locked' to the cup 22. The ledge 38 willthen be tightly gripped between the two washers 21,26, thus permittingonly a slight slip, between the cup and the casing or none whatever.

The shank 19, has a central bore for receiving the plunger or drill-lock33, behind which a compression spring 35 is inserted, tending to 'pushthe plunger downward. This plunger is provided with an inclined groove43, forming a key way for the bind ing screw 29, whichis threaded andcountersunk in the body '18,"so as not to protrude beyond itscylindrical surface when screwed in. The turned-down point of thisbinding screw 29 runs through the side of the shank 19 in order to beable to enter the groove 43, and hold the plunger from. turning. Theinclined bottom of this groove causes-a wedging between the plunger andthe binding screw 29 so that the greater'the pressure on the plunger,communicated from the drill 44, the harder will be-the binding of thescrew. The lower end of the plunger is formed to engage with the endo-f'a double ended drill 44 and is for thatpurpose'provided with prongs45,'which are made to engage inthe helical flutes of the drill. Throughthecooperation ofscrew 29 and plunger '33, the centering drill 44 isconsequently prevented from turning in the tool holder. It willtherefore be seen that this plunger acts not only as a drill look, butalso as a positive stop, preventing the drill from being pushed up, whenpressed against the work.

In the central bore of the body-piece 18, the cylindrical sleeve ordrill carrier 32 fits snugly, its upper end having a recess, into whichthe end of the plunger 33 is made to enter. The inner diameter of thesleeve coincides with that of the'drill 44 in order to give supportalong the whole length of the drill, and the outer diameter of the drillis the same as the diameter of the cylindrical opening 36 in the cup 22.As the length of the sleeve 32 is such that it will enter this hole 36-in advance of the drill point reaching the blank 42, any wabbling of thedrill is prevented, it being perfectly guided throughout its entirelength, close down to its working point during operation.

vanylubricant such as oil or soap-water that enters through the openings48 in the casing 20, will pass through the holes 47 and the conicalopening 46 and run down to the drill point, as well as passing on theoutside of the sleeve 32 and through grooves 37, collecting in theconical chamber in cup 22. No possibility of clogging does thereforeexist.

The sleeve 32 is held in place by means of a holdingscrew 28, which withits narrow end enters 'a corresponding hole in the -sleeve32. Thisholding screw is threaded and countersunk in the body 18 in the samemanner asscrew 29. The end of binding screw 28 is long enough to reachthrough the wall of thesleeve for the'purpose of clamping the drill 44in position. This clamping need however, only be very slight,

in order to hold the drill in engagement with the plunger 33, which, ashas already been described, locks'the drill against turning in the toolholder.

The two screws 28'and 29 are preferably situated with their center linesin the same axial plane-of the tool holder, and a longitudinal'slot-49is provided in the casing 20 located so as to register with the screws28 and 29, when the tool holder is compressed as shown in Fig. 8, andthe studs 30 engage the notches 27 The screws may then be reached fromthe outside and loosened by means of a screw driver, when the drillneeds re-setting.

Compression springs 36 are'housed in suitable chambers 50 provided inthe body '18. For protecting them against chips and dirt, their lowerends are inclosed in cylindrical tubes 34, which abut with theirbottom'ends against the upper surface of the cup retaining nut 25. Theouter diameter of the tubes is the same as that of the chamhers-50, intowhich they project sufliciently to be well guided. The springs 36 areinserted under compression so that they always tend to hold the parts inthe position indicated in Figs. 1, 2 and 3.

Ordinarily the sleeve 32 acts as a gage for determining the depth of thehole to be drilled, as the end of the sleeve will abut against the faceof the bar or blank to be centered and prevent the drill frompenetrating deeper into it, even if the drill continues to rotate.

for the tool holder, consisting of a plunger 53 which has a groove 52tapered similarly to the groove 43 in the drill lock 33. A set screw 51,threaded in the tool body 18 so as to be below the cylindrical surfaceof the tool body, engages in the groove 52, and by means of this screw,the axial position of the plunger might be changed. Both the plunger 53and its spring 54, which tends to push the plunger down, are housed in abore 55 provided to one side of the shank 19 in the body 18. By lettingthe end of plunger 7 53 project beyond the lower end surface of the toolbody, the plunger will abut against centering cup 22 sooner than thesleeve 32 abuts against the work piece, thus shortening the stroke ofthe tool sleeve and lessening the depth of the hole to be drilled.

Whenever it is desired to go back to the regular depth of the hole, allthat needs to be done is to push up and turn the casing20 on the body 18until the stud 30 entersthe recesses 27 then loosening the set screw 51with a screw driver, which can enter through a corresponding opening inthe casing, then to push back plunger 53 and re-set with the set screw51. Y I Fig. 11 shows a drill-setting gage 55 with a recessed portion 56corresponding in shape to the drill point. The use of this gage will beeasily understood. After push-, ing'the casing 20 up on the body '18 andturning it until locked by studs 30 in the notches 27, as alreadydescribed, the hold,- ing screws 28 and 29, which now register with theslot 49, are loosened with consequence that spring 35 partially pushesout the drill lock 33 and the drill 44. If now the gage is held over thedrill point and pushed up until its head strikes the end of the sleeve32, and the holding screws are retightened, the drill point willprotrude to exactly correspond with the recess in the gage and uniformholes may thereupon be drilled in a number of blanks, care being takenthat the drilling is continued until the sleeve 32 abuts against-thework piece.

In Fig. 9 the tool holder is shown in position on a drill press. A brakefor the centering cup in the form of a fork 57 is here provided. Theprongs 58 of the fork are shaped so as to embrace and tightly hold thecentering cup 22 when it enters between them, thus preventing therotation of the cup while engaging with the work piece or blank 42,although the rest of the tool holder rotates. I

The modified form of the centering tool illustrated in Figs. 13 and 14is intended to be used in connection with a chuck which 'is obvious thatall the holds the work piece firmly. In that case the centering cup isnot necessary. The lock 33 for the drill 44 and its spring 35 are allthe same as described above, the drill lock having an inclined key way43 engaging with a holding screw 29 which may be, as before, tapped inthe body 60 of the tool,

but preferably as here shown is tapped in the drill sleeve 61. Thesleeve in this case, is areceptacle both for the lock with its springand the drill 44. It dilfers further by being split longitudinally toform three grippers for the drill, no holding screw like 28 beingrequired. It 'is also provided with a swell 66 near its outer end. Thisswell is conical and engages with a corresponding recess in the toolbody 60, so that the sleeve will firmly grip the drill 44, on beingdrawn into the tool body 60, which is accomplished bymeans of theinterengaging threads at 62 of the sleeve and the tool shank 63. Theshank, which is revolubly mounted in the tool body 60, isiretainedtherein by means ofa washer 63 and screws 64. By turning the shank untilthe cone shaped swell 66 abutsa'gainst its recess'in the tool body, itparts will be firmly locked together. Similarly to the first embodimentof the invention, the sleeve 61 constitutes a depth gage, the end of thesleeve forming a positive stop when abutting against the work piece,thus governing the v depth of the hole to be drilled. The end is alsocup shaped as at 64 with the transverse holes '47 communicating with theconical recess forthe purpose of flushing. The sleeve 61 and the toolbody 60are non-revolubly connected by means of groove and pin 61. I

I claim 1'. A centering tool having a central member holding the drill,a casing slidably mountedrelative to said member, a centering cuprevolubly mounted on said casing at the drill end of the tool, said cuphaving a conical recess for receiving the workpiece, and a centralopening, the wall of which constitutes a support for the 'drill duringoperation and washers between said cup and said casing, for increasingthe friction, and means for taking up wear'on the washers.

2. A centering tool having a central member holding the drill, a casingslidably mounted relatively to said member, a centering cup revolublymounted on said casing at the drill end of the tool, said cup having ingat the drill end of the tool, said cup having a conical recess forreceiving the work-piece, and a central opening, the wall of whichconstitutes a support for the drill during operation; and means forincreasing friction between the cup and the casing, said meanscomprising washers and adjusting means therefor.

.4. A centering tool having a central member holding the drill, a casingslidably mounted relative to said member, a centering cup revolublymounted on said casing at the drill end of the tool, said cup having aconical recess for receiving the work-piece, and a central opening, thewall of which constitutes a support for the drill during operation; andmeans .for increasing friction between the cup and the casing; saidmeans comprising a ledge on said casing, a friction washer on eitherside of the ledge, one of said washers being loose and the other keyedto the cup.

5. A centering tool having a. central member holding the drill, a casingslidably mounted relative to said member, a centering cuprevolublymounted on said casing at the drill end of the tool, said'cuphaving a conical recess for receiving the work-piece, and a centralopening, the wall of which constitutes a support for the drill duringoperation; and means for causing friction between the cup and thecasing; said means comprising a ledge on said casing, a loose frictionwasher between said cup and the outer face of said ledge, a secondfriction washer keyed to said cup and engaging with the inner face ofsaid ledge; said second washer being provided with a plurality of keyholes, a nut threaded on said .cup and engaging with said second washer,a locking member in said nut constructed'to engage with any one ofsaidkey holes, wherebysaid nut may be adjusted either to permit freeturning of the cup relative, to said casing, or to lock cup and casingtogether by tightening said nut so as to set up considerable frictionbetween said ledgevand said washers.

6. A centering tool having a bodymember with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward,and provided with a wedgershaped key-way, deepening rearwardly, abinding screw threaded in said body member and adapted to engage in saidkey-way, whereby said plunger will be locked the firmer, the greater thepressure becomes on its forward end. I

7. A centering tool having a body member with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted to lock said plungerin said body member, the forward end of said plunger being constructedto firmly grip the end of thedrill, whereby said plunger in cooperationwith said holding screw, will prevent the turning of the drill relativeto said member.

8. A centering tool having a body member with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted to lock said plungerin said body member, the forward end of said plunger being constructedto firmly gripthe end of the drill, whereby said plunger in cooperationwith said holding screw, will prevent the turning of the drill relativeto said member, and means for holdplunger in cooperation with saidholding screw, will prevent the turning of the drill relative to saidmember, and means for holding the drill in engagement with said plunger;said means comprising a second binding screw threaded in said bodymember.

10. A centering tool having a body member with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward,and provided with a wedgeshaped key way deepening rearwardly, a bindingscrew threaded in said body member and adapted to engage in said keyway, whereby said plunger will be locked the firmer, the greater thepressure becomes .on its forward end, the forward end of saidplungerhaving prongs for engaging in flutes of the drill.

l1. Acentering tool having a body mem ber with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward,and provided with a wedgeshaped key way deepening rearwardly, a bindingscrew threaded in said body member and adapted to engage in said keyway, whereby said plunger will be locked the firmer, the greater thepressure becomes on its forward end, the forward end of said plungerhaving prongs for engaging in flutes of the drill, and means for holdingthe drill in engagement with said plunger; said means comprising asecond holding screw threaded in said body member.

12. A centering tool having a body member with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted to lock said plungerin said body member, a sleeve in said bore forming a carrier for thedrill, a

second binding screw threaded in said body member and adapted to holdsaid sleeve and the drill-in position; and means for keying the drill tosaid plunger so as to turn with it;

' 13. A centering tool having a body member ,with an axial bore, aspring-actuated plunger'in the bore tending to push the drill forward, abinding screw threaded in said body member adapted tolock said plungerin said body member, a sleeve in said bore forming a carrier for thedrill, a second binding screw threaded in said body member and adaptedto hold said sleeve and the drill inposition; and means for keying thedrill to said plunger so'as to turn with it; the nose of said sleevehaving a tapered recess around the drill pointand communicatingtherewith for flushing, and transverse openings for removing drillchips.

14. A centering tool having a body member with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted to look said plungerin said body member, a sleeve in said bore forming a carrier for thedrill, a second binding screw member and adapted'to hold said sleeve andthe drill in position; and means for keying the drill to said plunger soas to turn with it, a centering cup slidably mounted on said bodymember, said cup having a central opening corresponding in diameter tothe outside diameter of said sleeve and constructed to register with andguide said sleeve in advance of the-drill point reaching the work-piece.7

1,5. A centering tool having a body member with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted to lock saidlplungerin said body member, a sleeve in said bore forming a carrier for thedrill, a second binding screw threaded in said body member and adaptedto hold said sleeve andthe drill in position; and means for keying thedrill to said plunger so as to turn with it, a centering cup slidablymounted on saidbody, member, said cup having a central openingcorresponding in diameter to the outside diameter of said sleeve andconstructed to register with and guide said sleeve in advance of thedrill point reaching the workpiece; said opening being provided withrifle grooves for admitting a lubricant for the flushing and removing ofdrill chips.

16; A centering tool having a body member with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted to lock said plungerin said body member, a sleevein saidbore forming carrier for the drill,a. second threaded in said body binding screw threadedin said bodymember and adapted to hold said sleeve and the drill in position; andmeans for keying the drill to said plunger so as to turn with it; acasing provided with a guideway and slidably mounted around said bodymember, a centering cup on said casing at its forward end, a stop insaid body member engaging in said guideway in the casing and permittinglimited axial movement between them. i I

17 A centering tool having a body member with an axial bore, aspring-actuated plunger in thebo retending to push the drill forward, abinding screw threaded in said body member adapted to lock said plungerin said body member, a sleeve in said bore forming a carrier for thedrill, a second binding screw threaded in said body member and adaptedto hold said sleeve and the drill in position; and means for keying thedrill to said plunger so as to turn with it;

a casing provided with a guideway and slidably mounted around saidbodymember, a centering cup on said casing at its forward end, a stop insaid body member engaging in said guideway in the casing and permittinglimited axial movement between them, a spring tending to push said bodymember and casing apart, and a closed housing for, the spring,preventing grit from reaching it. g

18. A centering tool having a body member with an axial bore, aspring-actuated plunger inthe bore tending to push the drill forward, abinding screw threaded in said body member adapted to lock said plungerin said body member, asleeve in said bore form: ing a carrier for thedrill, a second binding screw threaded in said body member and adaptedto hold said sleeve and the drill in position; and means for keying thedrill to said plunger so as to turn with it; a cas ing provided with aguideway and slidably mounted around said body member, a centeringoup onsaid casing at its forward end, a stop in said body member engaging insaid guideway in the casing and permitting limited axial movementbetween them; a plurality of coiled springs; said body member providingseats for the springs, a closed housing for each spring, being guided atone end bysaid'seat and at the other end abutting against said cup.

19; A centering tool having a body mem ber with an axial bore, aspring-aotuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted to lock said plungerin said body'member, a sleeve in said bore forming a carrier for thedrill, a second binding screw threaded in said body member and adaptedto hold said sleeve and the drill in "position;'and'meansfOr keying thedrill to said plunger so as to turn with it;

body member providing seats for the springs, a closed housing for eachspring, being guided at one end by said seat and at the other endabutting against said clip; said guideway being L-shaped with itstransverse leg forward andprovided with a notch for said stop, in orderto lock the tool in its compressed position and uncover said bindingscrews, after the-"turning of the casing on the body member.

20. A vcentering tool having a body' member with an axial bore,- aspring-aetuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted to locksaid plungerin said body member, a sleeve in said bore forming a carrier for thedrill, a second binding screw threaded in said body member and adaptedto hold said sleeveand the drill in position; and means for keying thedrill to said plunger so as to turn with it; a casing provided with aguideway and slidably mounted around said body member,- a centering cupon said casing at its forward end, a stop in said body member engagingin said guideway in the casing and permitting limited H axial movementbetween them; a plurality of coiled springs; said body member providing.seats for the springs, a closed housing for each spring, being guidedat one end by said seat and at the other end abutting against said cup;said guideway being L-shaped with itstransverse leg forward and providedwith a notch for said stop, in order to lock the tool in its compressedposition, after the turning of the casing on the body member, saidcasing having a window for said binding screws, registering with themwhen the tool is in its compressed position.

21. A centering tool having a body member with an axial bore, aspring-actuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted to lock said plungerin said body member, a sleeve in said bore forming a carrier for thedrill, a second binding screw threaded in said body,

7 member and adapted to hold said sleeve and jeo the drill in position;and means for keying the drill to saidplunger'so as to turn with it; acasing provided with a guideway and slidably mounted around said bodymember, a centering cup on said casing at its forward end, a stop insaidbody member e'n-' gaging in said guideway' in the casing and permittinglimited axial movement between them; a' positive stop overning theamount of axial displacement between said cup and the drill.

22. A centering tool having a body member with an axial bore,aspring-actuated plunger in the bore tending to push the drill forward,a bindingcscrew threaded in said body member adapted tolock said plunslidably mounted around said body mem-' bet, a centering cup on saidcasing at its forward end, a stop in said body member engaging in saidguideway in the casing and permitting limited axial movement be-' tweenthem, a positive stop governing the amount of axial displacement betweensaid cup and the drill, said stop comprising a spring actuated pistoncarried in a suitable chamber provided in said body member, and a setscrew in said body member for adjusting the projecting length of saidpiston beyond the forward surface of said body member and' in thedirection of said cup.

'23. A centering tool having a body memher with axial bore, aspring-actuated plunger in the bore tending to push the drill forward, abinding screw threaded in said body member adapted tolock said plun 'erin said body member, a sleeve in said bore orming a carrier for thedrill, a second binding screw threaded insaid body member and adapted tohold said sleeve and the drill in position; and means for keying thedrill to said plunger so as to turn with it;va' casing provided with aguideway and slidably mounted around said body member, a centering cupon said casing at its forward end, a stop in said bodymember engaging insaid guideway in the casing and permitting limited axial movementbetween them, a positive stop governing the amount of axial'displacementbetween said cup and the drill, said'stop comprising a spring actuatedpiston carried in a suitable chamber provided in said body member, and aset screw in said body member for adjusting the pro-' jecting length ofsaid piston beyond the forward surfaceof said body member and in thedirection ofsaid cup; said guideway being L-shaped. with its transverseleg forward provided with a notch for said first stop,;in order to lockthe tool in its compressed position for resetting the drill aftertheturning of the sleeve on the body member; said casing having a windowfor said set' screw situated to register therewith when the tool is incompressed locked position; I M 1 24. A centeringv tool having a centralmember-holding the drill, a casing slidably mounted relative to saidmember, a centering cup revolubly mounted on said casing at the drillend of the tool, said cup having a conical recess for receiving the Workpiece; a brake for said cup mounted independently of and in fixedposition relative to said cup.

25. A centering tool having a central member holding the drill, a casingslidably mounted relative to said member, a centering cup revolublymounted on said casing at the drill end of the tool, said cup having aconical recess for receiving the work piece; a brake for said cupmounted independently of and in fixed position relative to said cup,said brake comprising a fork having vprongs constructed to embrace 26. Acentering tool having a central.-

member holding the drill, a casing slidably mounted relative to saidmember, a centering cup revolubly mounted on said casing at the drillend of the tool, friction increasing means between said cup and saidcasing, said cup having a conical recess for receiving the Work piece;said recess forming a receptacle for drill chips.

The foregoing specification signed at Syracuse, N. Y. this 16th day of July, 1914.

CHARLES J. BORGESON. In presence of C. GRAon KENTNER, ALEX. PALMER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

